Pathfinder Druid Help

[HMS Invincible]

My friends have started Pathfinder for the first time, but the DM has 2 brand new players who have never played any 3.x game before, which means me and a friend need to do the heavy lifting until they get their bearings. This makes me wonder, I was gonna replace my animal companion to get extra spells per day as a caster druid. How much can I get done with 3 spells per day at lvl 1 compared to having 2 spells, and an animal companion?

Also, after maxing Wis, I hear people are prioritizing Dex over Con. Why?